Problem: Simplify the expression. $(5r+7)(4r+2)$
Solution: First distribute the ${5r+7}$ onto the ${4r}$ and ${2}$ $ = {4r}({5r+7}) + {2}({5r+7})$ Then distribute the ${4r}.$ $ = ({4r} \times {5r}) + ({4r} \times {7}) + {2}({5r+7})$ $ = 20r^{2} + 28r + {2}({5r+7})$ Then distribute the ${2}$ $ = 20r^{2} + 28r + ({2} \times {5r}) + ({2} \times {7})$ $ = 20r^{2} + 28r + 10r + 14$ Finally, combine the $x$ terms. $ = 20r^{2} + 38r + 14$